Below are several announcements that would excite many within the Linux and open-source communities. Unfortunately, many of these are unlikely to happen in the foreseeable future.
NVIDIA opens up their Linux driver. This is very unlikely to ever happen. NVIDIA's binary driver is very mature and well-developed with a performance parity to the Windows driver as the code-base is largely shared between Windows / Linux / Solaris / FreeBSD. There's also nearly a feature parity across platforms, except for the Linux driver currently lacking support for "Fermi" overclocking, Optimus Technology, etc.
They wouldn't open-source their driver because they can't legally do so in some areas and they have no corporate reason to do so. Most Linux desktop (and especially workstation) users are content with simply installing the binary driver, when it "just works" well, is easy to update compared to open-source drivers where you need to replace several critical components of the Linux stack, and don't mind a tainted kernel. NVIDIA is also quick in supporting new kernel and xorg-server releases. It simply doesn't make any business or economical sense for NVIDIA to open up their driver.
NVIDIA Corp would also face various legal hurdles in every opening up their driver with regard to third-party licensed code, code that's patented (dealing with S3TC and other features), expose optimization secrets to their competitors, and code that could potentially put their Digital Rights Management support at risk. It's the same problems why AMD can't open up their Catalyst driver and why they invest in creating an open-source driver stack rather than just releasing the Catalyst code-base.
If/when NVIDIA backs a new (after abandoning xf86-video-nv) open-source strategy, it would likely come in the form of supporting the Nouveau project and/or publicly releasing technical documentation to the public.
OpenGL 3/4 support for Mesa. Support for the latest OpenGL specifications will eventually need to come to Mesa if the Linux desktop is ever to succeed. Mesa has been adding support for OpenGL 3.0 a bit at a time, but that specification is nearly three years old and is already outdone by OpenGL 3.1/3.2/3.3 and OpenGL 4.0/4.1. Mesa must also overcome some legal challenges such as dealing with floating-point textures and S3TC support, which is widely used by games and applications, but is covered by patents.
Steam / Source Engine for Linux. It really is coming whether you want to believe it or not.
When Steam and Source are natively on Linux, what game publisher will be the next to come. It would be interesting to see Crytek games on Linux, namely the Crysis series. However, the CryEngine used by these games is currently a Direct3D-only renderer, which would make a Linux port an even greater burden. What's more likely to come, and what will eventually be in place, is proper Direct3D 10/11 support in Wine. There's some Wine work towards DirectX 10, but it's still far from complete and will likely be a number of months before the latest Direct3D 10/11-only games are likely working well in this form.
Adobe brings Photoshop to Linux. While GIMP has improved a lot, there is no free software program that can yet match Adobe's Photoshop software. Some versions of Photoshop will work within Wine, but it would be wonderful to see Adobe provide a native Linux version of Photoshop. There's been interest and talk of doing so, but there doesn't appear to be any imminent plans to provide a native Linux version.
Open-source ARM/SoC graphics. It would be great to see open-source driver support (or at least reputable closed-source drivers) for more of the graphics cores being found in mobile devices and SoC designs. There's now efforts to reverse-engineer a PowerVR driver, a community Samsung OpenGL ES driver, and talk of a possible open PowerVR driver in Q3, but it would be great to see Qualcomm, Imagination Technologies, Samsung, Texas Instruments, and others step up their Linux support.
______________________. Something major in the X.Org / Linux graphics scene is to be announced within the next month or two. There is going to be some major announcement. I don't know what it is but other than I am told it will drive a lot of traffic to Phoronix. I have some ideas of what it might be based upon who is involved, but nothing concrete to stay. The last update I received (yesterday) on this mysterious project from a trusted source is, "if only one of the guys in charge gets back [from] of a well-deserved [vacation], and gives my side of the process a kick."
Other software that would be great to be ported natively to Linux: Microsoft Office, Rosetta Stone, and Intuit's products (at least now there's web-based versions of TurboTax, QuickBooks, etc).
id Tech 4 goes open-source. id Software is expected to open-source their id Tech 4 engine at some point just as they have done for previous generations of their engine. There's been talk that it may happen this summer at QuakeCon, since id Tech 4 is nearing the end of its useful commercial life, id Tech 5 will be here soon, etc. John Carmack previously expressed interest in releasing the id Tech 4 source when the id Tech 5 Rage game is out, which is still on target for release this year.
What other announcements would you ideally like to see that would benefit Linux? Share with us in the forums what your favorite announcements would be in the most optimistic world. Tomorrow we'll put on the pessimistic glasses and share what some of the most devastating announcements would be for Linux and open-source.